1. Field of the Invention
The present invention relates generally to an apparatus and method for charging a battery of a mobile terminal using sunlight, and more particularly to an apparatus and method for charging a battery of a mobile terminal using a thin film printed solar cell.
2. Description of the Related Art
Generally, a mobile terminal, such as a mobile phone, PDA (Personal Digital Assistant), and the like, uses batteries with electric cells, which are rechargeable. The discharge rate of the battery is in proportion to the usage of the mobile terminals. When the battery is discharged, the discharged battery is either replaced with another charged battery or charged by using a wire charger or a handsfree jack.
Such a battery may be charged by using a table charger, which directly contacts power terminals of the battery for charging, or by using an adapter charger, a handsfree jack of which is connected to a handsfree port of the mobile terminal. The above mentioned table charger is uncomfortable to carry because it needs a large mobile terminal stand for mounting and supporting the mobile terminal. Therefore, the adapter charger is now widely used.
However, the adapter charger is also uncomfortable to carry because it has an adapter body incorporating a plug to be inserted into an electrical outlet, a handsfree jack to be inserted into the handsfree port of the mobile terminal, and a power cable for low voltage to connect the adapter body and the handsfree jack. Moreover, the above mentioned adapter charger is impossible to use when the user goes on a long distance business trip in a car or where there is no electrical outlet. Namely, if the battery is fully discharged on a long distance trip, where charging of the battery of the mobile terminal from an electrical outlet may not be available, the user can no longer use the mobile terminal any more.
In order to solve these problems, a two-way battery charger for a mobile terminal including a sunlight charger as shown in FIG. 1 has been developed. Referring to FIG. 1, the two-way battery charger including the sunlight charger has a plurality of light collection plates attached to an outer surface of the mobile terminal, whereby the user can conveniently charge the battery using the charger without limitation of place.
However, when charging the battery, the above mentioned two-way battery charger including the sunlight charger should be positioned such that the rear face is directed to sunlight as shown in FIG. 1, so that the front face where an LCD window is disposed on is facing down. Therefore, the user can't immediately see information displayed on the LCD while charging the battery. In addition, the charging efficiency of this charger is low because the charging of battery is done through the solar cell area 100 corresponding to the area of the battery on the rear face of the mobile terminal. In addition, there is another problem in the conventional charger of FIG. 1 in that the solar cell mounted on the surface of the mobile terminal is vulnerable to external impact, and thus may be easily broken.